Electrical Properties Of Ferrites

Bi 2 fe 4 o 9 was prepared by solid state reaction and the electrical properties measured by impedance spectroscopy.

Electrical properties of ferrites.

The observed changes in these properties are brought about by a redistribution of cations. Polaron is formed and the electrical conduction occurs due to the hopping motion of small polarons. The most important family of hard ferrites has the basic composition mofe 2 o 3 where m is a barium ba ion or a strontium sr ion. High permeability to magnetic fields is particularly desirable in devices such as antennas.

After annealing in o 2 at 900 c bi 2 fe 4 o 9 is an electrically homogeneous insulator. The incorporation of rare earth ions r into the spinel lattice results in the occurrence of r fe interaction 3 d 4 f coupling that led to the improvement in the electrical and magnetic properties of the ferrites. Its high frequency permittivity is constant 14 1 over the temperature range 300 400 c and shows no evidence of incipient ferroelectricity at lower temperatures. These materials have a hexagonal structure and low in cost and density.

Although there are few reports on different properties of ni zn ferrite a systematic investigation about electrical properties is lacking so there is a need for investigation of electrical properties on ni zn ferrite to understand. Structural and electrical characterization of ni zn ferrites. Srinivasan and srivastava 27 have explained electrical properties of ferrites on the basis of tunneling of electrons amongst fe 2 and fe3 atoms on b sites. These are ceramic permanent magnetic materials.

Ferrites are usually ferrimagnetic ceramic compounds derived from iron oxides. The diverse properties of spinel lithium ferrites originate from their ability to incorporate a variety of transition metal cations into their lattice causing a subsequent change in their structural optical magnetic and electrical properties 9 10. The most important properties of ferrites include high magnetic permeability and high electrical resistance. Magnetite fe 3 o 4 is a famous example like most of the other ceramics ferrites are hard brittle and poor conductors of electricity.

Many ferrites adopt the spinel structure with the formula ab 2 o 4 where a and b represent various metal cations usually including iron fe. The electrical and magnetic properties of ferrites are influenced by the fe fe interactions spin coupling of the 3d electrons. Discussion on electrical properties of ferrites is generally explained by carrier hopping model or band structure. In the present investigation structural electric magnetic and frequency dependent dielectric properties of ferrite nanoparticles nps where and 0 8 prepared by sol gel autocombustion method were studied the crystallite size 46 89 58 40 nm was estimated from x ray diffraction data with the postconfirmation of single phase spinel structure.

Properties and applications of hard ferrites.